using System;

using System.Collections.Generic;

public class Program

{

    private static readonly List<string> Vovels = new List<string> { "а", "о", "е", "и", "ю", "я", "у", "э" };

    public static void Main()

    {

        var text = "Привет, дубина";

        var brickText = text;

        Vovels.ForEach(v => brickText = brickText.Replace(v, GetBrickTextForChar(v)));

        var normalText = brickText;

        Vovels.ForEach(v => normalText = normalText.Replace(GetBrickTextForChar(v), v));

        Console.WriteLine(brickText);

        Console.WriteLine(normalText);

    }

    static string GetBrickTextForChar(string textChar)

    {

        return textChar + "с" + textChar;

    }

}